Helper to deal with string encodings.

The new V8 datasource writes strings with Latin-1, UTF16Be or UTF16Le
encodings. This patch adds helper methods to convert those encodings to
UTF8

Bug: b/283794416
Change-Id: Ic4e629131c7d74594b0502b31bf0e1b02f8ac14b
diff --git a/Android.bp b/Android.bp
index 5c48dd4..07720b7 100644
--- a/Android.bp
+++ b/Android.bp
@@ -11175,6 +11175,7 @@
         "src/trace_processor/importers/proto/heap_graph_tracker.cc",
         "src/trace_processor/importers/proto/metadata_module.cc",
         "src/trace_processor/importers/proto/statsd_module.cc",
+        "src/trace_processor/importers/proto/string_encoding_utils.cc",
         "src/trace_processor/importers/proto/system_probes_module.cc",
         "src/trace_processor/importers/proto/system_probes_parser.cc",
         "src/trace_processor/importers/proto/translation_table_module.cc",
@@ -11311,6 +11312,7 @@
         "src/trace_processor/importers/proto/network_trace_module_unittest.cc",
         "src/trace_processor/importers/proto/perf_sample_tracker_unittest.cc",
         "src/trace_processor/importers/proto/proto_trace_parser_unittest.cc",
+        "src/trace_processor/importers/proto/string_encoding_utils_unittests.cc",
     ],
 }